Students model how scientists define organic molecules.
In this lesson, students examine the difference between the everyday (grocery store) use of the word organic and the scientific definition used in biology and chemistry. Rather than memorizing a definition, students build the concept of organic vs. inorganic through guided classification and comparison.
The lesson begins with a short activity that contrasts the colloquial and scientific meanings of organic. Students practice identifying which definition is being used in context and record their observations in a graphic organizer. At this point, the scientific definition is intentionally withheld so students can construct it themselves.
Next, students work in small groups to classify real-world objects as organic or inorganic. They receive feedback only on how many items are incorrectly placed, encouraging discussion, hypothesis testing, and revision. When students struggle, the teacher redirects them to sort by more meaningful criteria (such as food vs. non-food) to help them notice underlying patterns related to living things.
Once students have established a working model for organic and inorganic objects, they repeat the process with molecular diagrams. They use known reference points (such as DNA and water) to refine their classifications and infer the molecular features that distinguish organic molecules from inorganic ones.
By the end of the lesson, students are able to explain how scientists define organic molecules based on structure and composition, not on grocery store labeling. This lesson serves as a conceptual foundation for biomolecules units and prepares students to correctly classify carbohydrates, lipids, proteins, and nucleic acids.
This resource includes:
A digital interactive student lesson
Detailed teacher instructions
Object and molecule sorting tasks
A printable paper version
A printable literacy-based exit ticket
Teacher key
Grade & Course Recommendation:
Middle School:Grades 8, foundations of chemistry in life science.
High School:Grades 9–11 Biology or Chemistry, biochemistry introduction.
To preview this lesson, click here.
Cross-Curricular Connections:
Chemistry Integration: Comparison of carbon-based compounds and non-organic molecules.
ELA Integration: Reading comprehension and vocabulary development in scientific contexts.
Environmental Science Integration: Links to carbon cycles and organic matter in ecosystems.
Daily slide + literacy - based exit ticket included with purchase
HS-LS1-6: Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.
HS-LS1-1: Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins, which carry out the essential functions of life. (connection: biomolecules)
Science & Engineering Practices: Analyzing and interpreting data; Constructing explanations.
Crosscutting Concepts: Structure and Function; Patterns.
Common Core Alignment
CCSS.ELA-LITERACY.RST.9-10.4 / RST.11-12.4: Determine the meaning of domain-specific words and phrases as they are used in a scientific context (e.g., organic, inorganic, carbon-based).
CCSS.ELA-LITERACY.WHST.9-12.2: Write informative/explanatory texts, including the narration of scientific analyses (connection: explaining how molecular structure determines classification).
CCSS.ELA-LITERACY.RST.9-10.7 / RST.11-12.7: Integrate quantitative or technical information expressed in words with visual representations (connection: molecular models or chemical diagrams).
Students model how scientists define organic molecules.
In this lesson, students examine the difference between the everyday (grocery store) use of the word organic and the scientific definition used in biology and chemistry. Rather than memorizing a definition, students build the concept of organic vs. inorganic through guided classification and comparison.
The lesson begins with a short activity that contrasts the colloquial and scientific meanings of organic. Students practice identifying which definition is being used in context and record their observations in a graphic organizer. At this point, the scientific definition is intentionally withheld so students can construct it themselves.
Next, students work in small groups to classify real-world objects as organic or inorganic. They receive feedback only on how many items are incorrectly placed, encouraging discussion, hypothesis testing, and revision. When students struggle, the teacher redirects them to sort by more meaningful criteria (such as food vs. non-food) to help them notice underlying patterns related to living things.
Once students have established a working model for organic and inorganic objects, they repeat the process with molecular diagrams. They use known reference points (such as DNA and water) to refine their classifications and infer the molecular features that distinguish organic molecules from inorganic ones.
By the end of the lesson, students are able to explain how scientists define organic molecules based on structure and composition, not on grocery store labeling. This lesson serves as a conceptual foundation for biomolecules units and prepares students to correctly classify carbohydrates, lipids, proteins, and nucleic acids.
This resource includes:
A digital interactive student lesson
Detailed teacher instructions
Object and molecule sorting tasks
A printable paper version
A printable literacy-based exit ticket
Teacher key
Grade & Course Recommendation:
Middle School:Grades 8, foundations of chemistry in life science.
High School:Grades 9–11 Biology or Chemistry, biochemistry introduction.
To preview this lesson, click here.
Cross-Curricular Connections:
Chemistry Integration: Comparison of carbon-based compounds and non-organic molecules.
ELA Integration: Reading comprehension and vocabulary development in scientific contexts.
Environmental Science Integration: Links to carbon cycles and organic matter in ecosystems.
Daily slide + literacy - based exit ticket included with purchase
HS-LS1-6: Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.
HS-LS1-1: Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins, which carry out the essential functions of life. (connection: biomolecules)
Science & Engineering Practices: Analyzing and interpreting data; Constructing explanations.
Crosscutting Concepts: Structure and Function; Patterns.
Common Core Alignment
CCSS.ELA-LITERACY.RST.9-10.4 / RST.11-12.4: Determine the meaning of domain-specific words and phrases as they are used in a scientific context (e.g., organic, inorganic, carbon-based).
CCSS.ELA-LITERACY.WHST.9-12.2: Write informative/explanatory texts, including the narration of scientific analyses (connection: explaining how molecular structure determines classification).
CCSS.ELA-LITERACY.RST.9-10.7 / RST.11-12.7: Integrate quantitative or technical information expressed in words with visual representations (connection: molecular models or chemical diagrams).
